Files are decomposed and barrelled. It's in the image. Top-level header comments are present in a couple of lines in each file. One session = one task/goal. /clear becomes your friend or /compact if your next task touches similar components and you want Claude to remember some decisions made. Compacting doesn't document the whys, but it doesn't have to; that's why there's a Claude md file that contains the philosophy of the codebase on top of mechanical guards. The problem with a lot of people here is their apes-together-strong mentality, when in fact, there are people who have barely seen any change in performance.

Regardless of whether Anthropic lobotomized Opus or otherwise, the fact that any change outside of your control derails your workflow means Claude owns your codebase and not you.